Staple hammer



March 8, W49 w. J. VAIL STAPLE HAMMER Filed May 12, 1947 1NVENTOR.walter J; ma

Patented Mar. 8, 1949 STAPLE HAMMER Walter J. Vail, Chicago, Ill.,assgnor to Vail Manufacturing Company, Chicago, Ill., a corporation ofIllinois Application May 12, 1947, Serial No. 747,419

(Cl. 1-49l 8 Claims.

This invention relates to a manual implement for feeding and drivingstaples, tacks, or other fasteners, usually in strip form, and isadapted for operation in the manner of a hammer to drive the staples,tacks, or the like, into wood or other penetrable material.

It is a primary object of this invention to devise, for the purposementioned, an implement which is inexpensive, simple, sturdy inconstruction, and dependable in operation. In accomplishing these ends Iutilize a minimum of working parts, all of which are of rugged design.The construction attains lightness in weight, and is one that willafford years of hard service.

According to my invention, a sturdy linkage system connects a verticallyreciprocable driver with a pivoted work striker, this linkage comprisinga channelled arm enclosing a channelled link within which is contained awire spring which exerts an expansive force tending to restore the partsto their normal position of rest. This work striker itself is of duplexconstruction so as to embrace the channelled arm whereby to distributethrough spaced lines the thrust forces which are transmitted through theoperating parts. The spring being Wholly enclosed is better protected,and may be formed of wire which is contoured in duplex fashion so as todistribute its expansive force at a plurality of places.

Also, as a feature of my invention, 1' have devised a protecting casingfor the handle which contains a magazine, and for the head of theimplement as well. This casing is of general channelled form withopposite sides that are pivoted near one end to the head of theimplement and releasibly secured to the handle near its other end. Sucha casing, because of the mounting provided therefor, may be upwardlyswung so as to expose the top of the handle whereby the magazinetherewithin may be replenished with staples whenever the supply is low.Also, when the casing is swung back far enough, the operating partswhich are carried by the implement head are made accessible forinspection, cleaning, repair, or replacement. In addition, the forwardend of the guideway along which staples are advanced toward the head iscovered by a wall in spaced relation thereto, this Wall being formedwith an opening therethrough opposite the staple guideway so as topermit insertion of a tool to free the foremost staple if it be jammedat this point. This slotted Wallis normally enclosed by the casing but,when the casing has been swung upwardly and around a sufficientdistance, the slot is exposed to view so as to permit insertion of atool therethrough for the purpose indicated.

These and other objects of my invention, as will hereinafter appear, areattainable by a construction of which a certain preferred embodiment isset forth in the accompanying drawings, wherein:

Figure 1 is a longitudinal section through the implement in itsentirety, with a portion of the casing therefor shown in elevation;

Fig. 2 is a section in a generally horizontal plane, as indicated by theline 2-2 of Fig. 1;

Fig. 3 is a side elevational View of the head end of the implement, witha portion of the enclosing casing in longitudinal section, the Workingparts being shown in their operated positions; and

Figs. 4 and 5 are vertical sections, taken respectively on lines 4 4 and5-5 of Fig. 1.

The. present implement comprises an arm swingingly mounted upon a headcarried by a hollow handle in which is provided a magazine for holding asupply of staples or other fasteners; it comprises also means forautomatically feeding the staples or fasteners into driving position inthe hammer-head, and a driver positively released for actuation bymovement of a striker in response to impact with the work, the driverthen being free to advance against an operatively positioned staple todrive it into the Work. While the invention as illustrated and describedis referred to as an implement for driving substantially U-shapedstaples, it is to be understood that it may, with slight modification,feed and drive fasteners of other types, such as tacks, brads, nails, orthe like. Throughout the specication and claims, therefore, the termstaple is used to indicate broadly all forms of pointed fasteners whichmay be driven to position by the implement of my invention.

The working parts of my staple hammer are protected by an exteriorcasing C of channel form having an arched top wall I0 connecting a pairof spaced side walls I l. The casing top wall extends horizontally as ata. for the major portion of the length of the implement handle, thenrises upwardly at b to level off again through the head end region ofthe implement. At its forward end, the connecting wall Ill is extendeddownwardly at c to provide a front enclosure. At its rear end anenclosure is afforded by a depending connecting wall d whose lower endis inturned at e in the form of a lip adapted to be engaged by a springcatch l2 with which is connected an operating button I4. In its normaladvanced position, the catch engages the lip so as to prevent any upwardmovement of the casing at the rear end.

Within the casing is the implement framework comprising a longitudinallyextending channel rail R with flanges I at the top extending in wardlytoward each other, and therewithin a staple rail S channelled in crosssection to provide a top and spaced side walls depending therefrom andin their lower portions laterally offset to lie adjacent the inner sidesof the frame rail to which they may be xedly secured as by rivets I 6. Astick of staple s is adapted to stradd-le the staple rail, the legs ofthe staples depending into the spaces between the channel rail `and theinset upper portions of the staple rail. By some such means as this Iprovide a. magazine for the staple stick.

A channelled follower block I1 is adapted to ride on the staple rails Sbeneath the flanges I5 to engage with its forward edge the rearmoststaple whereby lto apply an endwise pressure to the entire stick.Secured to the top facevof this block between the flanges I5 is afitting having at its forward end an upstanding ear I8 and at itsopposite end a second ear I9 which provides a linger piece. To theforward ear is connected one end of a spring 20 in the form of .a ribbonadapted to be coiled about a pin 2I which is supported between spacedplates 22 secured as by rivets 2 3 to the channel rail R. By some suchmeans as this, a tension is maintained upon the staple stick tending toadvance it toward the head end 5f the implement along the staple railwhich serves as a guideway for this purpose.

The casing which forms a housing for the working parts of the implementis pivotally secured thereto at the head end as by means of a shaft 25which is extended transversely through an anvil block 21 as well as theadjacent walls of the channel rail R. This anvil block is thus securedin place adjacent the base of the implement head. Screw studs 28-may befitted tothe shaft ends, as shown. The anvil blockvat its forward end isspaced slightly from a front wall 30 which may be formed integral withthe channel rail R. A slot 3I is provided in the front wall for apurpose that will shortly be explained. The space 32 between the anvilblock and front wall 3U forms a way through which staples s may besuccessively driven downwardly into the work. This way is constituted inpart by a guide block 33 which is positioned just above the staple stickat the iront end of the guideway therefor, this block being secured byrivets 34 between upper extensions 35 of the side walls of the channelrail R. The anvil block 21 is also secured between these same walls asby rivets 36.

A simple and dependable means for driving the staples into the work is afeature of this invention. This may comprise a driver 31 in the form ofa heavy blade which is vertically reciprocable within the way 32 so asto engage, with each downward stroke, the top of the foremost staple sthat is then positioned in line therewith. This blade depends from ahead 38 through which is extended a pivot pin 39 whose opposite endstraverse elongated openings 40 in the spaced flanges 4I of a channelledarm A which at its rear end is pivoted by a pin 42 between the spacedWalls 22. The pin 33 establishes a pivotal and sliding connectionbetween the driver 31 and the arm A so as to permit the former toreciprocate within a vertical path While the latter is oscillatedthrough an arcuate path.

A pin 43 extending between the spaced flanges 4I of the arm A traversesthe spaced flanges 44 of a channelled link 45 which is fitted within thechannelled arm A so as to remain centered therewith. This link dependsfrom the arm to connect through a second pin 41 with the upper end 48 ofa work striker in the form of a bell crank lever L which is pivoted torock on the shaft 25. This lever is duplex in that it comprises a pairof spaced arms of like contour adapted at their upper ends to lie to theoutside of the arm flanges 4I. Below the shaft 25 these arms extendforwardly and below the anvil block toA join with a connecting bar 5Uwhich constitutes a striking nose. This nose lies just forwardly of theway 32 so that a staple s descending into the work will pass to theinside thereof.

The normal position of the operating parts is as indicated in Fig. 1. Inthis relationship they are maintained by the tension of a duplex wirespring 52 which is coiled about the pin 42 to form one leg a: whichextends to the pin 42 for connection therewith and a second leg y whichextends to the pin 41 for connection therewith (see Figs. 1 and 3). Thetension of the wire is expansive, whereby the legs :I: and y are urgedapart to increase the angle between the axes of the pins 42, 43 and 41.In consequence the arm A will normally be maintained in its upperposition (see Fig. 1) with the driver in elevated positiony above thelevel of the staple stick.

In operation, the implement head is advanced toward the workv with thestriker nose 50 aimed close to the point where a staple is to be driven.Upon impact of the striker with the work, its nose will .be raisedthereby rocking the striker to approximately theI position of Fig. 3.This same impact jolts the arm A with the result that its free end towhich the driver is connected will be downwardly moved. Because thestriker L and arm A then move oppositely, there will be little or nointerference of one with the other through the connecting link. Whetherone will amplify the force operating upon the other will depend uponsuch factors as the linkage ratio, the force of the impact, the strengthof the opposing spring, etc. The movement of the working parts takesplace very rapidly so that the endmost staple s in the stick isdisplaced by the acting end of the driver blade, and forced downwardlyinto the Work. When the implement is lifted from the work, the parts arerestored under the influence of the spring 52 to the position indicatedin Fig. 1.

Normally the casing C will remain in its enclosing position as indicatedby the showing in full lines in Fig. l. Its opposite side walls willthen extend down along the implement framework to enclose the handle andalso the operating parts within the head. This casing is secured inplace near its front end by the pivot pin 25 and at its rear end by thereleasable spring catch I2. A leaf spring 53 secured to the top wall Illof the casing engages resiliently with the top of the channel rail Rclose to its rear end to prevent looseness at that point. In case a newstick of staples vis to be introduced into the handle, the catch I2 isreleased to permit the casing to be lifted up to a position somewhat asindicated by the dot and dash lines in Fig. 1. If desired, the casingmay be swung through more than 90 so as to expose'the working parts inthe head. The simplicity of this operation whereby the parts interiorlyof the implement are exposed tends greatly to facilitate vreloading ofthe handle magazine as well as oiling, cleaning and repair of theoperating mechanism.

The movement range of the striker is between two stops one of which maybe the pin 43. In order thatthe initial position of the striker may beas shown in Fig. l, the arms 48 are recessed at 55 close to their upperends, the pin 48 then engaging with the edges of such recesses when thelever is retracted to its normal position. At the opposite Aextremity ofits rocking movement the striker engages with the confronting edges 56of the plates 22 at a point where recesses therein are provided toafford a desired amplitude of movement. Positive stops are therebyprovided for the striker lever in each of its opposite positions, andbecause of its link connection with the arm A the latter may also belimited in its movements by the same two stops. This means that when thedriver blade 3l has come to rest in a down position, where its actingend is disposed substantially at the surface of the work, the upper endof the striker lever will be abutting the plate stops 56, or be veryclose thereto.

A feature of this invention is the enclosing casing of sheet metal orthe like which is movably secured to the framework of the staple hammerin a way which is free from lost motion. To accomplish this, I employ apivotal connection near the forward end of the implement, the shaft 25whereon the casing is pivoted being provided with removable cap screws28 at its ends so that, when removed, the casing itself may also betaken on or the implement. The spring catch at the rear end. of thecasing holds the latter securely in position against movement relativeto the framework of the implement in cooperation with the leaf spring 53which maintains a constant tension upon the top of the channel rail R toprevent any play or lost motion at this point. Obviously it is a simplematter to release the casing at the rear end for a limited upwardswinging movement which will be ample for replenishing the supply ofstaples in the hammer magazine; it is equally simple to continue theswinging movement of the casing through 180 or more whereby to exposethe operating parts at the head end of the implement. This will permit aready inspection, cleaning, or oiling of any of the parts. It alsoaffords access for a tool to be entered through the front slot 3| toloosen any staple that may be clogged at the way 32. In these operationsit is necessary only to release the spring catch I2 preliminary toswinging of the casing to either of these positions just noted.

The spring 52 is one which remains protected within the enclosing wallsof the channels of the arm A and link 45. It is so formed and disposedas to occupy a minimum of space, and on account of its duplex character(see Fig. 2) exerts an abundance of force for return of the operatingparts to their normal position as indicated in Fig. 1. Its mounting inoperative position involves no additional parts since it utilizes forthis purpose only the three pins 42, 43, and 41 which pivotallyinterconnect the linkage system of the arm A and striker lever L. Thisis an important advantage from the standpoints of cost and assembly.

I claim:

l. A staple hammer having a handle with a head at one end, and stapledriving mechanism carried by the head comprising a verticallyreciprocable driver, an arm extending longitudinally of the head andpivoted thereto at its rear end and at its front end having a slidingpivotal connection with the driver, a work striker in the form of alever located below the arm and pivoted intermediately of its ends tothe head and having forwardly of its pivot point a nose which is movableupwardly by impact with the work, a link pivoted to the work striker ata point rearwardly of its pivotal connection with the head and inpivotal connection with the arm intermediately of its ends whereby thedriver and arm are moved downwardly together whenever the striker noseis moved upwardly upon impact with the work, and a spring in engagementvwith the three pivotal connections (l) in the rear of the arm, (2)between the arm and link, and (3) between the link and lever exerting anexpansive force tending to move the upper end of the lever forwardly andraise the arm and driver upwardly.

2. A staple hammer having a handle with a head at one end, and stapledriving mechanism carried by the head comprising a verticallyreciprocable driver, an arm having a sliding pivotal connection with thedriver and rearwardly thereof a pivotal connection with the head, a workstriker in the form of a lever pivoted intermediately of its ends nearthe base of the head and extending both forwardly therebelow andrearwardly thereabove, a link pivotally interconnecting the arm and thelever near its upper end which latter is adapted in one extreme positionto engage the pivotal connection between the link and the arm, and stopmeans rearwardly of the upper end of the lever adapted to engage thesame when the latter has been rocked about its pivot to its oppositeextreme position.

3. A staple hammer having a handle with a head at one end, and stapledriving mechanism carried by the head comprising a verticallyreciprocable driver, a channelled arm having a sliding pivotalconnection with the driver at one end, a channelled link tted within thechannel of the arm and pivotally connected thereto intermediatelythereof, a striker having spaced arms on opposite sides of the arm andpivoted to the link, a pivotal connection between the striker and thehead, and spring means enclosed within the channels of the arm and thelink exerting an expansive force tending to raise the arm and with itthe driver blade.

4. A staple hammer having a handle with a head at one end, and stapledriving mechanism lcomprising a vertically reciprocable driver, a

pivoted work striker, a channelled linkage system interconnecting thedriver and striker, and spring means for restoring the driver andstriker to initial positions disposed wholly within the channelledlinkage system for protection thereby.

5. A staple hammer having a handle with a head at one end, and stapledriving mechanism comprising a vertically reciprocable driver, a pivotedwork striker, a pivoted linkage system interconnecting the driver andstriker, and a pair of stops engageable successively by the work strikerfor limiting its range of pivotal movements, one of the said stops beinga pivot pin included in the pivoted linkage system.

6. A staple ha-mmer having a handle with a head at one end, and stapledriving mechanism carried by the head comprising a verticallyreciprocable driver with a weighted upper end, a channelled armembracing at its forward end the Weighted upper end of the driver and insliding pivotal connection therewith, a pivotal connection between therearward end of the arm and 7 the head, a channelled link fitted Withinthe ehannelled arm and pivotally connected thereto at a pointintermediatels7 of its ends, a work striker in the form of a duplexlever pivoted intermediately of its ends at a point close to the base ofthe head near the forward end thereof, the lever extending bothforwardly and downwardly from its pivot point and upwardly and,rearwardly thereof to embrace the channelled arm, .a pivotal connectionbetween the duplex lever and the chanelled link, stop means carried bythe head opposite the upper end of the lever for arresting the rearwardmovement thereof, the `duplex link in its other extreme position beingadapted to engage the pivotal connection between .the channelled linkand the channelled arm, and. spring means contained wholly 4within thechannelled link and channelled arm exerting an expansive force tendingto straighten lthe angle between the pivotal connections between (1) thelink and the arm, (2) the link and the lever, and (3) the lever and thehead.

7. A staple hammer having a handle with a head at one end, and stapledriving mechanism carried by the head comprising a Work striker pivotedintermediately of its ends to the head adjacent its base, a verticallyreciprocable driver, means interconnecting the striker and driverincluding an arm'pivoted to the driver at Ione end and to the head atthe other end, a link pivoted at one end to the arm and .at its otherend to the striker, the arm having a channelled cross section embracingthe link .and the lever being duplex to embrace the arm, and springmeans -contained wholly within the arm and link extending from thepivotal connection between the arm and the head to the pivotalconnection between the arm and the link and thence to the pivotalconnection between the link and the lever, exerting an expansive forcetending to widen the 4angle between the axes of these three points.

8. A staple hammer having a handle with a head at one end, the handlecomprisinga channel rail closed by a front wall through which is a slot,.an anvil block carried by the channel rail close to the front endthereof but spaced from the slotted front wall to provide avertical waytherebetween, means for advancing staples processionally along thechannel rail to a point in alignment with the way, staple drivingmechanism carried by ythe head adapted with each operation to displacethe foremost staple-downwardly through the way for advance into thework, a channelled protecting-casing enclosing the handle and head, apivotal connection between opposite walls of the casing and theimplement head, and a releasable connection between the casing and thehandle adjacent its rear end such as to permit the casing, when free, tobe swung upwardly above the handle and forwardly thereof whereby toexpose the operating mechanism carried by the head, including theslotted front wall of the channel rail whereby to afford access to theforemost staple positioned in the way.

WALTER J. VAIL.

REFERENCES CITED UNITED STATES PATENTS Name Date Vancura Aug. 7, 1945Number

